.box{
    margin: 20px auto;
    width: 700px;
    height: 500px;
}

.container {
  width: 100%;
  height: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 20px;
  box-sizing: border-box;
}

.left {
  font-size: 70px;
  user-select: none;
  cursor: pointer;
}

.right {
  font-size: 70px;
  user-select: none;
  cursor: pointer;
}
#canvas_1{
  width: 100% !important;
  height: 100% !important;
}
.flex{
  display: flex;
}
.slider{
  flex: 1;
  margin-left: 10px;
}